Roof supporting means for mines



Aug. 3, 1965 L. J. ARNOTT 3,197,966

ROOF SUPPORTING MEANS FOR MINES I Filed Feb. 14, 1961 4 Sheets-Sheet l LESLFE I- ARN TT INVENTOR:

Aug. 3, 1965 1.. J. ARNOTT ROOF SUPPORTING MEANS FOR MINES 4 Sheets-Sheet 2 Filed Feb. 14, 1961 INVENTORZ LESLIE I ARN TT BY 9 ATTVa ROOF SUPPORTING MEANS FOR MINES Filed Feb. 14, 1961 4 Sheets-Sheet 3 LESLi E J. ARNOTT A-rfKs.

INVENTOR;

Aug. 3, 1965 J. ARNOTT ROOF SUPPORTING MEANS FOR MINES 4 Sheets-Sheet 4 Filed Feb. 14, 1961 INVENTOR:

LESLI J. ARNOTT ATTVS.

United States Patent 3,197,966 ROOF SUPPORTING MEANS FOR MINES Leslie John Arnott, Chasetown, near Walsall, England, assignor to Gullick Limited, Wigan, England, a British company Filed Feb. 14,1961, Ser. No. 89,159 Claims priority, application Great Britain, Feb. 18, 1960, 5,708/60 4 Claims. (Cl. 6145) This invention is for improvements in or relating to roof supporting means for mines.

The invention is more particularly concerned with selfadvancing or walking roof supports. Such supports incorporate means (e.g. hydraulic ram devices) which enable the support to move itself forwardly as stripping or cutting of the coal face proceeds, the support also serving generally to push over the coal conveyor to the newly exposed coal face.

According to the present invention there is provided a self-advancing or walking mine roof support which comprises at least two roof-supporting units or elements arranged in tandem and articulated one to the other.

In one preferred embodiment of the invention one unit or element of the support comprises three or four legs or props whilst the other comprises a single leg or prop. These two units or elements are articulated together at their upper and lower parts. In one convenient arrangement one unit or element has a cantilever roof-bar articulated to it which extends over and beyond the other unit and rests on the upper part thereof.

Conveniently the two units or elements are coupled together at their lower part by a pair of links pivotally attached, by pivot pins or the like, to each of the units or elements.

Where the articulated cantilever roof-bar rests on the upper part of a prop or props it is preferable to provide a concave-convex or ball-and-socket-like seating arrangement so that the props and the cantilever roof-bar can accommodate themselves one to the other.

Two particular embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings wherein:

FIGURE 1 is a side elevation partly in section of one embodiment,

FIGURE 2 is a plan view of FIGURE 1,

FIGURE 3 is a fragmentary detail plan view of a part of the support shown in FIGURE 1 with its upper part removed,

FIGURE 4 is a side elevation of the second embodiment, and

FIGURE 5 is a plan view of FIGURE 4.

Referring first to the embodiment of the invention shown in FIGURES 1, 2 and 3, the support in this case comprises two units or elements. One of these units, hereinafter referred to as the major unit, comprises a base having sockets 31 in which are mounted four hydraulically extensible props or legs 32 which support at their upper parts roof-bars 33.

The other unit comprises a foot 34 having a socket 35 in which is mounted a single hydraulically extensible leg or prop 36. It will be noted from FIGURE 1 that this leg or prop is held in its socket by means of a rubber or other flexible or resilient ring 37 which permits limited movement of the prop or leg in its socket. A similar arrangement may be adopted in the sockets for the legs of the major unit 30, 31, 32. The prop 36 rests on an extension piece or lift 38 which is also located in the socket'by a flexible or resilient ring 39.

A cantilever form of roof-bar 40 is articulated to and between the roof-bars 33 of the major unit as indicated at 41 and rests on the upper part of the single leg 36 of ice the minor support. It will be noted that the roof-bar extension 40 is provided on its underside with a seating 42 having a concave recess which bears on a convex upper part of the leg or prop 36 so that the one can accommodate itself to the other.

Located in the lower part of the major unit and projecting therefrom is a double-acting hydraulic ram 43, the ram or thrust bar proper of which passes freely through an opening or arch 44 in the foot 34 and is adapted to be coupled as indicated at 45 to a bracket 46 on the coal conveyor C.

After a cut of the coal face has been made the ram can be operated to push over the coal conveyor to the newly exposed coal face and then by lowering the props and'retracting the ram the roof support comprising the a two units is drawn up to the conveyor. The chock is then re-secured between floor and roof.

A guard 47 is located over the ram. A valve 48 is provided for controlling the supply of pressure fluid to the props and ram.

At its lower part the major unit is connected to the foot 34 by (see FIGURES 1 and 3) a pair of tie-bars or links 49 pivotally attached to the units as indicated at 50 and 51.

The embodiment of the invention shown in FIGURES 4 and 5 is similar to that already described with reference to FIGURES 1, 2 and 3 and where applicable like reference numerals have been used to indicate like parts. In this arrangement, however, the major unit comprises three props or legs 32 instead of four and its roof-bar 52 is in the form of a triangular canopy having a forwardly projecting part 53 to which the cantilever roof-bar extension 40 is articulated.

At their lower parts the two units are connected together by links 54, the connection to the minor unit being in the form of a gimbal as indicated at 55.

The props or legs have convex base ends which rest in their sockets as indicated at 56, the sockets being provided with resilient or flexible bushes 57 and 58.

The flexibility provided between the two units or elements of the support above described enables it, as a whole, to adjust itself to any inequalities in floor and/or roof.

To sum up, the chock above described, as compared with known forms of four-leg chocks, has the following advantages:

(1) It gives support to the roof up to the conveyor.

(2) It reduces floor lift ahead of the chock.

(3) The cantilever bar is more effective because of the reduced overhung length.

Furthermore, as compared with a five-leg chock as available heretofore, the chock above described has the following advantages:

(1) It is structurally more suitable for pit use.

(2) The front leg is tied by pivoting members to the body of the chock and is hence more stable during drawing forward.

(3) It is located relatively close to the conveyor, being fastened thereto by the ram.

(4) The pivoted link connection from the front leg to the main body of the chock allows the unit to conform to floor irregularities without imposing high stresses in the members.

I claim:

1. A self-advancing mine roof support comprising a pair of roof support units each having a base and disposed one behind the other for location adjacent a conveyor, a fluid pressure advancing ram operatively connected to the base of one of said units and adapted to be connected to said conveyor to independently advance the conveyor and the units as a pair, and rigid link means of constant length hingedly connecting the base of the .4 rear unit to the base of the forward unit so as to permit step-like elevation of one base with respect to the other and to transmit a forward thrust exercised by said advancing ram from said one base to which it is connected to the other base to advance both units together.

2. A self-advancing mine roof support according to claim 1 wherein said link means comprises at least one elongated rigid member pivotally connected at each end to said bases.

3. A self-advancing mine roof support according to claim 1 wherein said base of the forward unit is provided with a forwardly directed through opening, said advancing ram being fixed to and at least partially housed within the base of said rear unit and including a thrust part disposed in alignment with and passing freely through said opening in the base of the forward unit for coupling to a conveyor.

. 4. A self-advancing mine roof support according to claim 1 wherein extensible prop means are provided mounted in each of said bases, a' roof structure supported on prop means of the rear unit, a cantilever roof supporting means resting on prop means of the forward unit at a point intermediate the length of said cantilever means, and pivot means connecting the rear end of said cantilever means to the roof structure of the rear unit. 25

4 References Cited by the Examiner UNITED STATES PATENTS 2,910,281 10/59 Wilkenloh et al. 262-43 FOREIGN PATENTS 1,164,448 5 5 8 France. 1,192,850 4/59 France. 1,197,458 6/59 France. 1,211,437 10/59 France. 1,250,713 12/60 France. 7 773,407 4/ 57 Great Britain. 786,331 11/57 Great Britain. 854,967 11/60 Great Britain.

OTHER REFERENCES French Patent No. 1,184,882, 2/59 (British corresponding No. 830,704, 3/60).

French Patent No. 1,193,591, Apr. 27, 1959, (British corresponding Nos. 827,696, 2/60 and 853,822, 11/60).

Great Britain Patent No. 845,727, 8/60 (corresponding to French Patent No. 1,211,437, 10/59).

CHARLES E. OCONNELL, Primary Examiner.

WILLIAM I. MUSHAKE, EARL J. WITMER,

Examiners. 

1. A SELF-ADVANCING MINE ROOF SUPPORT COMPRISING A PAIR OF ROOF SUPPORT UNITS EACH HAVING A BASE AND DISPOSED ONE BEHIND THE OTHER FOR LOCATION ADJACENT A CONVEYOR, A FLUID PRESSURE ADVANCING RAM OPERATIVELY CONNECTED TO THE BASE OF ONE OF SAID UNITS AND ADAPTED TO BE CONNECTED TO SAID CONVEYOR TO INDEPENDENTLY ADVANCE THE CONVEYOR AND THE UNITS AS A PAIR, AND RIGID LINK MEANS OF CONSTANT LENGTH HINGEDLY CONNECTING THE BASE OF THE REAR UNIT TO THE BASE OF THE FORWARD UNIT SO AS TO PERMIT STEP-LIKE ELEVATION OF ONE BASE WITH RESPECT TO THE OTHER AND TO TRANSMIT A FORWARD THRUST EXERCISED BY SAID ADVANCING RAM FROM SAID ONE BASE TO WHICH IT IS CONNECTED TO THE OTHER BASE TO ADVANCE BOTH UNITS TOGETHER. 